Device and method for closing and sealing containers



Dec. 15, 1959 H. LEHMANN 2,916,351

DEVICE AND METHOD FOR CLOSING AND SEALING CONTAINERS Filed March 26. 1952 INVENTOI Harry Le/lklahh ATTORNEY United States Patent k 2,916,861 e DEVICE AND METHOD on CLOSINGJAND 1 l SEALING CONTAINERS r 7 Harry Lehmann, Puchheini; near Munich, Germany Application March 26, 1952,, Serial Ne. 278,571 a 3Claims. (21.5342

This invention relates to a device for closing and sealing containers formed of sheet fibrous material, such 2,916,861 Patented Dec. 15, 1359 out the process of this invention whereby thecurvatures of the beadsare somewhat enlarged orderto more clearlydemonstrate theprocedure. 1

Fig. 1 andFig. 3 represent a cross section through a beaded container and through the drawn cover placed on said container, Fig. 1 representing a cover with a low flange and Fig; 3 a cover with a high'flange.

Fig. 2 and Fig. 4 show the cover ,"flanges headed to such an extent that the formed bead almost contacts the bead of the container casing. e i

Fig. 5 shows both beads in almost fully compressed state.

The device for makings. closure according to this invention consists, in principle, of a heatedbeading tool 8 as paper and the like, and more particularly to a device for closing and sealing containers of said type that are provided with a beaded upper edge, and to a method of closing and sealing. such containers.

Various closures for containers and like'packing material are known. Thus, for instance, the bead of a container is united with a top part fastened to the edge of the container whereby said top part is folded together only when transporting said container. Furthermore it is known to provide beaded-containers below the 'bead with an. externally extending groove into which a cardboard liquid-tight because, on beading, bottom and casing and their layering are dislocated with respect to each other.

It is one object of this invention to provide a closure for containers formed of sheet fibrous material, such as paper and the like, which is liquid-tight and sufliciently resistant to withstand the strains imposed thereon on shipping and transporting the filled container without causing said closure to become leaky, thereby avoiding the disadvantages of the known closures.

Another object of this invention resides in the provision of a novel means and method for closing and sealing beaded containers formed of sheet fibrous material, such as paper and the like, said method being highly efficient in operation, yet relatively simple and economical to perform and being especially adaptable for use at the point where the containers are to be filled.

A further object of this invention is to provide a device for carrying out said process of tightly closing and sealing beaded containers, thereby rendering said closure not only liquid-tight but also so stable and resistant that it will satisfy any requirement.

Other objects of this invention will become apparent from the specification and the examples given therein.

According to this invention a drawn cover is placed over the bead of the container casing, the edge of said cover extending somewhat over the bead of said casing.

Said cover edge is beaded by means of a beading tool which moves towards the bead of the container casing. Beading of the cover edge is continued until theformed bead rests upon the existing bead of the container casing. Both beads are then jointly forced, by a further movement of the heading tool, against a die which supports the cover and are firmly pressed together. The height of the cover flange and the diameter of the curvature of the bead are preferably proportioned in such a manner that the edge of the cover, after beading, is situated inside the container bead.

The attached drawings illustrate a device for carrying provided with an inner beading recess which alsos'erves to compress the beads, and counter-die 7 which'ser'ves as prop on beading the edge 4 .of-coverz and as support on compressing the heads 3 and'S. The container to be closed and sealed is placed with the drawn cover 2 put thereon, between said beading tool 8 and said die 7. Die 7 holding cover 2 in its position, presses said cover 2 gently upon container casingLwhich is provided with bead 3. The heated. beadingtool's moves towardsbead 3 of container casing 1. Thereby flange 4 of cover 2 (Fig. 1 and Fig. 3) isjbeaded into shape 5 until it'contacts bead 3' (Fig. 2. andFig. 4).

' "Ifheifeby beading tool 8 proceeds continuously inits direction or movement," thus, "forcing both beads against dief 7 and compressingthe same. Fig, 5f'showsjthe two beadsin almost fully compressed-state 6. Flange 4 of cover 2 is preferably of such a height that, in the beaded state, it projects into the inside of the existing bead 3 of the container casing (Fig. 4). Both beads are firmly pressed together in this position. This has the efiect that the cutting edges are unable to swell under the influence of moisture reaching the container from the outside. The diameter of the curvature of the two beads is selected in accordance with the wall thickness of container casing 1 and cover 2 in such a manner that it is possible to firmly press together both beads at the narrowest position between beading tool 8 and die 7.. When using containers coated with paraffin, both beads are fused together by the pressure and the heat of beading tool 8. When using impregnated containers it is also possible to achieve fusion of the compressed beads under the influence of heat and pressure when using thermoplastic synthetic resins.

On closing and sealing by pressing the beads together, the container and, likewise, the container casing are not subjected to any stress or strain because the pressure for compressing is intercepted and absorbed by die 7. Therefore, container casing 1 and cover 2 can 'be made very light and thin depending upon the intended use of said container.

By the process of this invention, a.container closure is obtained which is absolutely liquid-tight. "The edge of the container, produced under the influence of heat and pressure, considerably reinforces and strengthens the same and renders it substantially indifferent towards the stresses and strains occurring when shipping and transporting such filled containers.

Containers closed and sealed according to the method and with the device of this invention, may safely be used for shipping and transporting milk, cream, honey, syrup, marmalade, sauces, meat, fish, and fruit salads and others more. They may also serve for air-tightly packing aromatic goods, such as coffee, cocoa, and spices. They are especially suitable for transporting, shipping, and storing of hygroscopic materials, such as dried milk products, preparations containing glucose and others.

Of course, it is understood that the device according to this invention is provided with means for supporting means for supplying electric current to said heating unit.

As stated above, the containers may be formed of any sheet fibrous material, such as paper and synthetic resins. Plasticized paper or fiber, vinyl acetate, cellulose acetate, cellulose nitrate or other thermoplastic material may also be used. Especiallysuitable are containers formed'from paper combined with foils of synthetic resins or provided with a coating thereof. Of course, any other similar material may be used likewise.

I claim:

1. A device for closing and sealing containers made from fibrous sheet material, said containers tapering from top to bottom and being provided with beaded edges, said device comprising a counter-die serving as prop on heading the downwardly extending flange of a cover placed over said container, and as support on pressing together the resulting bead of said cover with the bead of said container, said counter-die having a substantially flat horizontal lower surface, and a beading tool movable in upward direction towards said counter-die, said beading tool having a rounded upper opening part for receiving and guiding the cover flange, a cylindrical guiding part for guiding said cover flange, and a rounded beading recess for forming a bead of said cover flange over and into the beaded edge of said container and for firmly compressing the beads of said cover and container, the lower inner opening of said beading tool having a larger diameter than the outside diameter of the container casing at the place of beading and compressing t 1 4 I the beads, the cylindrical guiding part of said beading tool having a height corresponding at least to the height of the cover flange, and the diameter of said beading recess being such that its inner edge does not contact the container wall at the starting place of the beaded edge of said container.

2. A method of closing and sealing containers of fibrous sheet material which comprises providing a container tapering from top to bottom and having an external bead along the upper edge thereof, placing a substantially flat cover thereon, said cover having a downwardly extending flange, inserting said container and cover in a hollow beading tool with said flange in contact with the inner guiding walls of said tool and said container being out of contact with said tool, the latter having an internal shoulder at its lower end, placing a counter-die on said cover, then moving said tool towards said die to cause said flange to first curl inwardly on said shoulder and then contact said bead, and finally cause said flange and bead to intercurl, whereby only the bead of said container is subjected to the pressure of said tool and die, and pressing said bead and flange together.

3. A method according to claim 2, in which said die is stationary and said tool moves toward said die.

References Cited in the file of this patent UNITED STATES PATENTS 180,356 Marquet July 25, 1876 2,120,901 Moore June 14, 1938 FOREIGN PATENTS' 793,770 France Nov. 23. 1935 

